Montelukast for Allergies and Asthma

Montelukast for Seasonal Allergies and Asthma: Understanding Its Role

If you or your child has asthma and hay fever, you may have heard of a daily tablet rather than an inhaler that is used for both. That tablet is montelukast. It is widely prescribed in Australia, and it also carries some important safety information that every patient and carer should know about.

This article explains what montelukast is, what it is approved for, and what to watch for. It is general education only. It is not personal medical advice and gives no dosing information.

What Is Montelukast?

Montelukast is a modern, synthetic medicine developed in the late 1990s. It belongs to a group called leukotriene receptor antagonists (LTRAs). In Australia it is a Schedule 4 (prescription-only) medicine, so you need a prescription from a doctor.

Traditional Use, Early Research and Approved Uses

It helps to keep three categories separate.

Traditional use

There is none. Montelukast is a laboratory-developed pharmaceutical. It has no history in traditional, Indigenous or herbal medicine, so any product claiming a "natural" version of montelukast should be treated with caution.

Early research and how it works

In the 1990s, researchers identified chemical messengers called cysteinyl leukotrienes. These are involved in airway inflammation, mucus production and tightening of airway muscles during allergic reactions and asthma flare-ups.

Early clinical work showed that montelukast blocks CysLT1 receptors in the respiratory tract. In simple terms, it interferes with one of the signals the body uses to set off allergic and asthma-related airway responses. Triggers for these responses include pollen and physical exertion. This mechanism is described in Australian Prescriber.

Proven and approved uses in Australia

The Therapeutic Goods Administration (TGA) has approved montelukast for:

Chronic asthma: long-term preventive use in adults and children aged 2 years and over, either on its own or as an add-on to inhaled corticosteroids.
Exercise-induced asthma: helping to prevent airway narrowing brought on by exercise.
Seasonal allergic rhinitis (hay fever): relief of daytime and night-time symptoms in adults and children aged 2 years and over.

Whether it is suitable for a particular person is a decision for their doctor.

A Preventer, Not a Reliever

This is the point most often misunderstood. Montelukast is a daily preventer. It cannot stop a sudden asthma attack and it does not replace a fast-acting reliever inhaler such as salbutamol.

Illustrative example: Sam, a teenager, takes a preventer tablet and starts wheezing during a footy match. The tablet will not relieve that wheeze. Sam needs to follow his Asthma Action Plan and use his reliever inhaler, and seek urgent help if it does not work. Anyone with asthma should have a written action plan from their doctor. Asthma Australia has information on add-on asthma medicines.

Why Might a Doctor Choose It?

For hay fever, montelukast should generally be reserved for people whose symptoms are not adequately controlled with other treatments or who cannot tolerate them. Inhaled corticosteroid-based treatment is generally preferred for asthma; difficulty with inhalers should also prompt technique and spacer review.

Montelukast works differently from inhaled corticosteroids, and it comes as a tablet. This gives doctors several reasons to consider it:

As an add-on when an inhaled steroid alone is not enough.
When asthma and hay fever occur together, since it is approved for both.
When someone finds inhaler technique difficult, such as some young children.

Illustrative example: A parent tells their GP that their six-year-old has asthma and spring hay fever, and struggles with their puffer. The GP may discuss whether a tablet fits into the overall plan. Only a clinician who knows the child’s history can make that call.

Safety: Mood and Behaviour Changes

Many people take montelukast without problems. Mild effects such as headache and stomach upset are commonly mentioned. However, the TGA requires prominent warnings in the Product Information and Consumer Medicine Information about neuropsychiatric events. Reported effects include:

sleep problems, including nightmares and insomnia
anxiety
agitation and irritability
depression
rarely, suicidal thoughts or actions

You can read the TGA safety alert and the Healthdirect medicine information for more detail.

What patients and carers can do

Know the warning signs before starting. Read the Consumer Medicine Information leaflet.
Watch sleep and temperament, especially in children, who may not describe their feelings.
Stop montelukast and contact a doctor immediately if new or worsening mood, behaviour or sleep symptoms occur. Do not wait for them to pass. Continue following the asthma action plan and obtain advice about replacement treatment.
Seek emergency help for immediate danger. In Australia, call 000 if someone is at immediate risk of self-harm or has severe breathing difficulty.

Illustrative example: A mother notices her son has started having vivid nightmares and is unusually irritable a couple of weeks after beginning a new medicine. She does not wait to see if it settles. She stops montelukast and contacts the GP immediately for advice and a review of asthma treatment.

Access in Australia

Montelukast requires a prescription. Whether a particular prescription is subsidised on the Pharmaceutical Benefits Scheme (PBS) can depend on the circumstances, such as the patient’s age and the reason it is prescribed. Your pharmacist or doctor can explain what applies to you.

Frequently Asked Questions

Can montelukast stop an asthma attack?
No. It is a daily preventer. Reliever inhalers are used for sudden symptoms, as set out in your asthma action plan.

Is it approved for hay fever?
Yes. In Australia it is approved for relief of daytime and night-time symptoms of seasonal allergic rhinitis in adults and children aged 2 and over.

Can children take it?
It is approved for children aged 2 years and over for the uses above. A doctor decides if it is appropriate for an individual child, and carers should watch closely for mood or sleep changes.

Can I buy it over the counter?
No. It is Schedule 4, which means prescription-only.

What should I do if I notice mood changes?
Stop montelukast and contact a doctor immediately for new or worsening mood, behaviour or sleep symptoms. Call 000 in Australia for immediate danger.

Conclusion

Montelukast is a well-established, prescription-only tablet with approved roles in long-term asthma prevention, exercise-induced asthma and seasonal hay fever. It is a preventer, not a rescue medicine, and it carries a clear regulatory warning about mood and behaviour changes. If you are considering it for yourself or your child, talk to your GP or pharmacist about whether it suits your situation and what to watch for. Read the Consumer Medicine Information leaflet and keep your asthma action plan up to date.

This article is for general education only and does not replace advice from a registered healthcare professional.